In September of 2009, Malcolm J. Casadaban, a molecular genetics professor at University of Chicago, died from exposure to a form of bubonic plague, only 12 hours after he was admitted to the hospital. Dr. Casadaban had been studying Yersinia pestis, or septicaemic plague; however, university officials maintain that the strain had been weakened to make it safe for research.

The source of Dr. Casadaban's illness was not discovered until too late. The revelation that he had died from exposure to the same plague bacteria he had studied for eight years led to a slew of questions. If the bacteria was supposed to be safe for research, how could this have happened? After eight years of studying the bacteria, why did Dr. Casadaban only contract it now? And if he contracted the disease in the laboratory and then went out into the world, might others have caught it?

The Centers for Disease Control and Prevention are investigating the incident along with the University of Chicago, but details about Dr. Casadaban's death and his experiments have been held tightly by the University, even from his own family. Dr. Casadaban's family is still trying to learn what led to his death, and answers from the University and the CDC have remained far from forthcoming. One can hardly help but wonder: are the investigators stumped, or is there something they are keeping to themselves?